An Effective PCC Voltage Harmonic Compensation and Harmonic Power Sharing in Islanded Microgrid

Abstract

This paper proposes an enhanced virtual impedance control strategy to achieve the accurate harmonic power sharing as well as PCC harmonic compensation at the same time without degrading the reactive power sharing accuracy. The proposed control strategy is achieved by modifying the virtual impedances at fundamental and harmonic frequencies simultaneously, and the mismatched impedance between distribution generators (DGs)is effectively compensated with the improved fundamental and harmonic power sharing performance. Based on inverter modelling, the comparative frequency domain of the inverter output impedance and controller is analyzed. And also, the central controller is removed by means of the distributed communication network, which reduces the system complexity and increases the stability and reliability of the whole microgrid. The reliability and effectiveness of the proposed control strategy are experimentally validated together with theoretical analysis.